THE AUK : 
A QUARTERLY JOURNAL OF 
ORNITHOLOGY. 
vol. x. October, 1893. no. 4. 
ON THE CHANGES OF PLUMAGE IN THE BOBO- 
LINK ( DOLICHONTX ORTZIVORUS). 
BY FRANK M. CHAPMAN. 
In a previous number of ‘The Auk,’ 1 I described, under the 
above title, the changes which occur in the plumage of the Bobo- 
link, with particular reference to the manner in which the breeding 
plumage of the male is acquired. This latter point was one on 
which considerable difference of opinion existed, but the question 
seemed to be settled by a specimen in the American Museum of 
Natural History (No. 32,783, H. H. Smith, Corumba, Matto 
Grosso, Brazil, March 1, 1886) which showed clearly the charac- 
ter of the spring change of plumage. 
This specimen is apparently unique and exhibits in a remark- 
able degree the extent of a change in color which, in a compara- 
tively short time, occurs solely through fading and a wearing 
away of the exposed tips of many of the feathers. 
When compared with a specimen in which, through these 
causes, the ‘full’ or black plumage has been acquired the differ- 
ences are so great that it is difficult to believe they can have 
occurred without an actual moult. For this reason the Editors of 
‘The Auk’ have decided to figure the Corumba specimen and 
1 Vol. VII, 1890, pp. 120-124. 
l8o 
General Notes. 
The Change from Winter to Spring Plumage in the Male Bobolink 
( Dolichonyx oryzivorus). — I have been much interested in Mr. Chap- 
man’s articles on the “spring moult” of the Bobolink (Auk, VII, 1893, 
p. 120; and X, 1893, p. 31 1), but after reading them I could not help asking 
myself two questions : Does the adult male Bobolink always have a 
spring moult except when caged? If so, how can we explain the fact 
that in captivity the same change in plumage may take place absolutely 
'without any sign of moulting? 
As I must leave these questions unanswered, let me add a few words 
about a pet Bobolink I once owned. 
The bird was in the usual black breeding plumage when I first had 
him, but during the fall there %vas a complete moult, and he became the 
well known Reed-bird of the South. Always having had the impression 
that the Bobolink must also moult when changing from the winter to the 
summer dress, I was very much surprised in this case to find no feathers 
in the cage at any time during the spring, though I looked carefully for 
them myself day after day. The change in color, however, went steadily 
on, beginning with the appearance of a black feather here and there, 
until, having passed through a kind of intermediate ‘pie-bald’ stage, my 
bird looked once more as he did when I first had him the previous 
summer; except that the black was not quite as deep, though very nearly 
so, nor was the yellowish white so clear as at first. All at once, before 
the change was complete, he burst into full song, and kept it up until 
fall, when he moulted, and was again the yellowish brown bird of the 
preceding autumn. 
There was no doubt about the autumnal change being a true moult 
during this or the preceding fall, as the feathers about the cage and the 
‘pin-feathers’ on the bird fully proved, and the absence of any true moult 
in spring was shown with equal certainty by the absence of these same 
proofs. 
In the autumn I gave my Bobolink to a friend, who only succeeded in 
keeping him a few weeks; so this was the last of one of the happiest birds 
it was ever my good fortune to possess. — James Skillen, Harvard 
Medical School , Boston , Mass. frnkr XI. April. 1884 Pi 180 
